Hi:
Here' s one approach:
> int <- sample(1:20,10)
> m <- matrix(sample(1:40, 20), nrow = 10)
> int
[1] 7 12 4 6 1 19 17 20 15 5
> m
[,1] [,2]
[1,] 9 15
[2,] 23 32
[3,] 40 14
[4,] 19 38
[5,] 28 6
[6,] 26 18
[7,] 34 22
[8,] 7 35
[9,] 21 3
[10,] 39 12
> m[m[, 1] %in% int, ]
[,1] [,2]
[1,] 19 38
[2,] 7 35
HTH,
Dennis
On Fri, Apr 1, 2011 at 10:08 PM, Joseph N. Paulson
<[email protected]>wrote:
> Hi all!
>
> I have a vector, let's say for example int <- sample(1:20,10);
> for now:
>
> now I have a matrix...
> M = m x n
> where the first column is a "feature" column and most likely shares at
> least
> one of the int (interesting) numbers.
>
> I want to extract the rows where int[] = M[,1]
>
> I thought:
> rownames(int)<-int;
> rownames(M)<-M[,1];
>
> M[rownames(int),] would work, but it doesn't... (I assume because I have
> rownames(int) that are not found in M[,1]. Neither does,
> rownames(M)==rownames(int)...
>
> Any help would be greatly appreciated!
>
> Thank you!
>
> [[alternative HTML version deleted]]
>
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> and provide commented, minimal, self-contained, reproducible code.
>
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